A radio frequency (RF) plasma-enhanced vapor deposition reactor, commonly called the Reinberg system, is typically used for deposition of polysilicon and amorphous silicon, among other things. The system employs a pair of capacitive plates, at the center of which an inert gas, such as helium or argon, containing 5% silane (SiH.sub.4) is introduced and caused to flow radially outward between the two plates. On one of the plates, heaters are disposed on one side, and substrates on which silicon is to be deposited are on the other side of the plate so as to be warmed by the heaters. RF power is applied between the two plates to create a plasma, thus decomposing the silane and causing the silicon to be deposited on the substrates. One problem with such a system is that the application of too much RF power causes the formation of fine silicon particulates, resembling snow. On the other hand, utilization of too little RF power causes the formation of polymeric forms of silicon/hydrogen, such as SiH.sub.2, which is a gummy substance that can coat the entire system and render it inoperable. In prior systems, the deposition process is very inefficient; a significant amount of the silane is converted into particulates, rather than being converted into deposited silicon. This provides low rates of deposition on the one hand (on the order of 100 angstroms per minute to 200 angstroms per minute), and limits the time (on the order of minutes) the system can be run before it becomes clogged with particulates, on the other hand. This means that if thick layers of deposited silicon are desired, they cannot be deposited in a single cycle; use of multiple cycles results in nonuniformities and other poor quality characteristics of the resultant product, particularly due to surface contamination between runs. Thus, the provision of very thick films of silicon is not commercially feasible with such devices. The foregoing problems are further compounded in cases where the temperature is kept very low (less than 200.degree. C.), such as when depositing amorphous silicon on microelectronic circuits or other devices which would be ruined at higher temperatures.